Effect of HPC molecular weight on granules and tablets prepared by two wet granulation methods
January 2018 edition of Tablets & Capsules magazine features an article co-authored by Edmont Stoyanov, Berna Ehlig and Wade Tanev.
In this edition of the column, researchers from Nisso present the results of a study that examined how the molecular weight (MW) of different hydroxypropyl cellulose (HPC) grades affected the characteristics of granules and tablets prepared by two wet granulation methods: high shear and fluid bed.
Wet granulation is one of the most commonly used methods of developing solid dosage drug products. Among the advantages of this classical granulation method
over other technologies are a narrow particle size distribution (PSD) of the granules, few fine particles that yield little dust, more consistent powder flow, better control of granule size, very good binder homogeneity, and good powder compatibility.
The most important excipient group in a successful wet granulation formulation is the binder. Within this group are polymers with different chemistries, mechanical properties, and viscosity ranges. The polymer binder HPC has attracted the attention of formulators in the last decade due to its superior mechanical properties, chemical stability, and multi-functionality. This cellulosic ether appears to work even in challenging formulations with high dose, poorly compressible drug products, where other binders usually fail. Low-viscosity (low-MW) HPC grades are used as a binder for all types of wet granulation including highshear, fluid-bed, extrusion, and melt granulation. To select the suitable grade, scientists often must conduct many experiments, adjusting the desired powder and tablet characteristics. In this study, we focused on the influence of the HPC MW on the granule and tablet characteristics in fluid-bed and highshear wet granulation.